A Compact Blast-Induced Traumatic Brain Injury Model in Mice

Blast-induced traumatic brain injury (bTBI) is a common injury on the battlefield and often results in permanent cognitive and neurological abnormalities. We report a novel compact device that creates graded bTBI in mice. The injury severity can be controlled by precise pressures that mimic Friedlander shockwave curves. The mouse head was stabilized with a head fixator, and the body was protected with a metal shield; shockwave durations were 3 to 4 milliseconds. Reflective shockwave peak readings at the position of the mouse head were 12 6 2.6 psi, 50 6 20.3 psi, and 100 6 33.1 psi at 100, 200, and 250 psi predetermined driver chamber pressures, respectively. The bTBIs of 250 psi caused 80% mortality, which decreased to 27% with the metal shield. Brain and lung damage depended on the shockwave duration and amplitude. Cognitive deficits were assessed using the Morris water maze, Y-maze, and open-field tests. Pathological changes in the brain included disruption of the blood-brain barrier, multifocal neuronal and axonal degeneration, and reactive gliosis assessed by Evans Blue dye extravasation, silver and Fluoro-Jade B staining, and glial fibrillary acidic protein immunohistochemistry, respectively. Behavioral and pathological changes were injury severity-dependent. This mouse bTBI model may be useful for investigating injury mechanisms and therapeutic strategies associated with bTBI.